This invention relates to a scaffolding system for performing a work on an outer wall surface of a building.
For peforming works such as repair, coating or tiling on an outer wall surface of a building, chimney, petroleum tank or the like, it is necessary to provide a protective net over the wall surface. For providing the protective net, it has heretofore been conventionally practiced to construct a scaffolding with steel pipes along the wall surface and stretch a protective net over the entire area of scaffolding, fixing the protective net to the pipes constituting the scaffolding by means of clips. The works on the wall surface are performed by workmen standing on the pipe scaffolding. It however requires much time and cost to construct and disjoint the pipe scaffolding. It is particularly so when the works are performed on an outer wall surface of a multistoried building. Moreover, the conventional pipe scaffolding is inconvenient in that the outer wall surface of the building must be covered with the scaffolding and the net all the time until the work is finished.
For overcoming such inconveniences, the assignee of the present invention has proposed, as disclosed in Japanese Patent Publication No. 57-40313, a scaffolding system utilizing hanging stages. According to this scaffolding system, as shown in FIGS. 1 and 2, parapet wall hooks 3 are provided with intervals therebetween on a parapet 2 on the roof of a buiding 1. Hanging stages 6 are suspended from these parapet wall hooks by means of cables which are tied at the upper end thereof to the parapet wall hooks 3 and wound on winding drums 7 provided in the respective hanging stages 6. Each hanging stage 6 is capable of ascending and descending by driving the winding drums 7 and has a stop member 5 secured to the lower inside portion thereof and extending towards an outer wall surface 4 of the building 1 for stopping falling pieces. The hanging stages 6 are arranged horizontally along the outer wall surface of the building 1. Protective nets 9 are secured to the cables 8 or auxiliary cables (not shown) which extend from the parapet wall hooks 3 to the hanging stages 6 by means of clips 10. Thus, the protective nets 9 are stretched between the parapet wall hooks 3 and the hanging stages 6 so that the entire outer wall surface of the building 1 is covered with the protective nets 9 with a necessary space A defined between the protective nets 9 and the ourter wall surface 4. Working gondolas 12 which are suspended from the parapet wall hooks 3 by means of cables 11 and can ascend and descend by themselves are disposed in the space A. By ascending or descending these working gondolas 12 by driving self-ascending and descending device 13, works such as repair, coating and tiling are performed on the outer surface of the building 1.
In this prior art scaffolding system, the hanging stages 6 are gradually moved up or down in accordance with the progress of the work on the outer surface of the building 1. More specifically, when the work is started from the ground and is progressed towards the roof of the building 1, the hanging stages 6 are gradually lifted in accordance with the progress of the work performed by workmen working on the working gondolas 12 and the protective nets 9 which have become unnecessary due to lifting of the hanging stages 6 are taken in the hanging stages 6 as they are detached from the cables 8 or the auxiliary cables. Conversely, when the work is started from the top of the building 1 and is progressed towards the ground, the hanging stages 6 are gradually lowered in accordance with the progress of the work and the protective nets 9 which have been stored in the hanging stages 6 are taken out of the hanging stages 6 and attached to the cables 8 or the auxiliary cables by means of the clips 10. According to this prior art scaffolding device, the conventional pipe scaffolding can be obviated and therefore the time and costs which have been required for constructing and disjointing the pipe scaffolding can be saved and besides it becomes unnecessary to cover the entire outer wall surface of the building all the time until the work on the outer wall surface is finished.
This prior art scaffolding system, as well as the conventional pipe scaffolding, has the disadvantage that, if a work on the outer surface of a building is to be continued for days under the condition that the outer wall surface is kept covered with the protective nets, there sometimes occurs damage in the protective nets due to strong wind.
It is, therefore, an object of the invention to provide an improved scaffolding system for performing a work on an outer surface of a building which has eliminated the above described disadvantage of the prior art scaffolding system.